Vapor chamber and manufacturing method of the same

ABSTRACT

A heat dissipating device includes a first casing includes a recessed portion, and a second casing coupled to the first casing. The recessed portion at least partially defines an evaporator section of the heat dissipating device, a condenser section of the heat dissipating device is disposed surrounding the recessed portion, and the first casing and the second casing enclose an internal space of the heat dissipating device. The heat dissipating device further includes a plurality of first support structures arranged in the recessed portion, a plurality of second support structures arranged in the condenser section, and a plurality of heat transfer structures arranged in the recessed portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application is a divisional application ofnon-provisional application Ser. No. 16/870,297 filed May 8, 2020, whichclaims priority under 35 U.S.C. § 120 to U.S. provisional applicationNo. 62/846,268 filed May 10, 2019, the entire contents of both theseapplications are hereby incorporated by reference.

BACKGROUND

During operation of electronic devices, the heat generated by theprocessors must be dissipated quickly and efficiently to keep operatingtemperatures within manufacturer recommended ranges. As these electronicdevices increase in functionality and applicability so does operatingspeed of the processors used therein. With each new generation ofelectronic devices being thinner and more compact, thermal management ofthese devices becomes challenging as spacing between the different heatsources in the electronic devices is reduced.

Vapor chambers are used to dissipate heat. In general, vapor chambersare formed by flattening heat pipes to around 30% to 60% of theiroriginal diameter or bonding an upper and lower casing together. Vaporchambers are vacuum containers that carry heat from a heat source byevaporation of a working fluid which is spread by a vapor flow fillingthe vacuum, thereby increasing the thermally connected surface area. Thevapor flow eventually condenses over cooler surfaces, and, as a result,the heat is uniformly distributed from an evaporation surface (heatsource interface) to a condensation surface (larger cooling surfacearea). Thereafter, condensed fluid flows back to near the evaporationsurface. A wick structure is often used to facilitate the flow of thecondensed fluid by capillary force back to the evaporation surface,keeping the evaporation surface wet for large heat fluxes.

The thermal performance of vapor chambers is dependent on theeffectiveness of the vapor chambers to dissipate heat via the phasechange (liquid-vapor-liquid) mechanism. The capillary force generated inthe wick structure must overcome the liquid pressure drop in the wickand vapor pressure drop in the vapor chamber. The capillary forcegenerated is lower when the vapor chambers are thin, as the liquidpressure drop and vapor pressure drop are higher when spacing isreduced. Additionally, in such an example, to minimize thermalresistance, small feature sizes for structures are typically designednear the evaporation surface. The low porosity and permeability of thesmall feature sized evaporation surface structures, compounded withsintered powdered wicks having high capillary force and having highliquid pressure drop, often increase fluid resistance to sustaincapillary force driven flow throughout the wick structures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective top view illustrating a vapor chamber,according to embodiments of the disclosure.

FIG. 1B is a perspective bottom view of the vapor chamber of FIG. 1A,according to embodiments of the disclosure.

FIG. 1C is a plan view of the vapor chamber of FIG. 1A, according toembodiments of the disclosure.

FIG. 1D is a cross-sectional view of the vapor chamber along line 1D-1Din FIG. 1C, according to embodiments of the disclosure.

FIG. 1E illustrates portions of the first inner surface and the secondinner surfaces, the plurality of heat transfer structures, and theplurality of first support structures including wick structures.

FIG. 2A is a perspective top view illustrating the first casing of thevapor chamber of FIG. 1A including a working pipe, according toembodiments of the disclosure.

FIG. 2B illustrates a portion of the evaporator section in FIG. 2A inrelative detail, according to embodiments of the disclosure.

FIG. 3A is a perspective top view of the first casing of the vaporchamber of FIG. 1A, according to embodiments of the disclosure.

FIG. 3B is a perspective view illustrating a portion of the evaporatorsection in FIG. 3A in relative detail.

FIG. 4A is a perspective top view illustrating the first casing 110 ofthe vapor chamber 100, according to embodiments of the disclosure.

FIG. 4B is a perspective view illustrating the evaporator section inFIG. 4A in relative detail, according to embodiments of the disclosure.

FIG. 5A is a perspective top view of the first casing of the vaporchamber, according to embodiments of the disclosure.

FIG. 5B is a perspective view a portion of the evaporator section inFIG. 5A in relative detail.

FIG. 6A is a perspective top view of the first casing of the vaporchamber, according to embodiments of the disclosure.

FIG. 6B is a perspective view illustrating a portion of the evaporatorsection in FIG. 6A in relative detail.

FIG. 7A is a perspective top view of the first casing of the vaporchamber, according to embodiments of the disclosure.

FIG. 7B is a perspective view illustrating a portion of the evaporatorsection in FIG. 7A in relative detail.

FIG. 8 illustrates a flowchart of a method for manufacturing a vaporchamber, according to embodiments of the disclosure.

It should be understood that the drawings are not to scale and that thedisclosed embodiments are sometimes illustrated diagrammatically and inpartial views. In certain instances, details that are not necessary foran understanding of the disclosed method and apparatus, or that wouldrender other details difficult to perceive can have been omitted. Itshould be understood that the present application is not limited to theparticular embodiments illustrated herein.

DETAILED DESCRIPTION

The present application is now described more fully hereinafter withreference to the accompanying drawings, in which embodiments are shown.Embodiments can, however, be embodied in many different forms and shouldnot be construed as being limited to the various embodiments set forthherein; rather these embodiments are provided so that this disclosurewill be thorough and complete and will fully convey the scope of theexample embodiments to those of ordinary skill in the relevant art.

Like numbers refer to like elements throughout. In the figures, thethickness of certain lines, layers, components, elements or features canbe exaggerated for clarity. Where used, broken lines illustrate optionalfeatures or operations unless specified otherwise.

The terminology used herein is for the function of describing particularembodiments only and is not intended to be limiting the exampleembodiments. As used herein, the singular forms “a,” “an” and “the” areintended to include plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises” or “comprising,” as used herein, encompass the notions of“including” and “having” and specify the presence of stated features,integers, steps, operations, elements components and/or groups orcombinations thereof, but do not preclude the presence or addition ofone or more other features, integers, steps, operations, elements,components and/or groups or combinations thereof.

The use of “for example” or “such as” to list illustrative examples doesnot limit to only the listed examples. Thus, “for example” or “such as”means “for example, but not limited to” or “such as, but not limited to”and encompasses other similar or equivalent examples. As used herein,the term “and/or” includes any and all possible combinations or one ormore of the associated listed items, as well as the lack of combinationswhen interpreted in the alternative (“or”). As used herein, the terms“embodiment” or “present embodiment” are non-limiting terms and notintended to refer to any single aspect of the particular embodiment butencompass all possible aspects as described in the specification and theclaims.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as knowingly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, such as those defined inknowingly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of thespecification and claims and should not be interpreted in an idealizedor overly formal sense unless expressly so defined herein. Well-knownfunctions or constructions cannot be described in detail for brevityand/or clarity.

It will be understood that when an element is referred to as being “on,”“assembled” to, “connected” to, “coupled” with, “contacting,” etc.,another element, it can be directly on, assembled to, connected to,coupled with and/or contacting the other element or intervening elementscan also be present. In contrast, when an element is referred to asbeing, for example, “directly on,” “directly assembled” to, “directlyconnected” to, “directly coupled” with or “directly contacting” anotherelement, there are no intervening elements present. It will also beappreciated by those of ordinary skill in the relevant art thatreferences to a structure or feature that is disposed “adjacent” anotherfeature can have portions that overlap or underlie the adjacent feature.

Spatially relative terms, such as “under,” “below,” “lower,” “over,”“upper” and the like, can be used herein for ease of description todescribe an element's or feature's relationship to another element's orfeature's as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is inverted, elements described as “under” or “beneath” otherelements or features would then be oriented “over” the other elements orfeatures. Thus the exemplary term “under” can encompass both anorientation of over and under. The device can otherwise be oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly. Similarly, the terms“upwardly,” “downwardly,” “vertical,” “horizontal” and the like are usedherein for the function of explanation only, unless specificallyindicated otherwise.

It will be understood that, although the terms first, second, etc., canbe used herein to describe various elements, components, regions, layersand/or sections, these elements, components, regions, layers and/orsections should not be limited by these terms. Rather, these terms areonly used to distinguish one element, component, region, layer and/orsection, from another element, component, region, layer and/or section.Thus, a first element, component, region, layer or section discussedherein could be termed a second element, component, region, layer orsection without departing from the teachings of the present application.The sequence of operations (or steps) is not limited to the orderpresented in the claims or figures unless specifically indicatedotherwise.

Embodiments as disclosed herein are directed to vapor chambers having aworking fluid therein, and manufacturing methods of the same. For thepurposes of discussion, embodiments are directed to heat dissipationdevices including vapor chambers. However, embodiments are equallyapplicable to other types of heat dissipation devices without departingfrom the scope of the disclosure.

FIG. 1A is a perspective top view illustrating a vapor chamber 100,according to embodiments of the disclosure. FIG. 1B is a perspectivebottom view of the vapor chamber 100 of FIG. 1A, according embodimentsof the disclosure. FIG. 1C is a plan view of the vapor chamber 100 ofFIG. 1A, according to embodiments of the disclosure. FIG. 1D is across-sectional view of the vapor chamber 100 along line 1D-1D in FIG.1C, according to embodiments of the disclosure. For the sake ofexplanation, the dimension of the vapor chamber 100 in the X directionis considered as the length, the dimension in the Y direction isconsidered as the width (breadth), and the dimension in the Z directionis considered as the thickness. Referring to FIGS. 1A to 1D, the vaporchamber 100 includes a first or bottom casing 110 and a second or topcasing 190 coupled to each other and defining an internal space 101 ofthe vapor chamber 100. The vapor chamber 100 includes an evaporatorsection 114 having a plurality of first support structures 154. In someembodiments, the plurality of first support structures 154 are column(or pillar) like structures. The vapor chamber 100 further includes acondenser section 116 and a condenser vapor flow area 120 between theevaporator section 114 and the condenser section 116 (also see FIG. 2A).The condenser section 116 includes a plurality of second supportstructures 176. In some embodiments, the plurality of second supportstructures 176 are column (or pillar) like structures. In someembodiments, and as illustrated, the evaporator section 114 is centrallylocated in the vapor chamber 100 and the condenser section 116 islocated along the periphery of the vapor chamber 100 surrounding theevaporator section 114. However, in other embodiments, the evaporatorsection 114 is offset from the center. As illustrated, the evaporatorsection 114 extends or protrudes a certain distance from a first contactsurface 112 of the first casing 110. The vapor chamber 100 and theevaporator section 114 are illustrated as having a generallyquadrangular shape. However, embodiments are not limited in this regard,and the vapor chamber 100 and the evaporator section 114 can have otherdesired shapes.

In embodiments, the first casing 110 and the second casing 190 furtherinclude a first contact (or outer) surface 112 and a second contact (orouter) surface 192, a first inner surface 119 and a second inner surface199, and a first bonding edge 118 and a second bonding edge 198,respectively. On a side of the vapor chamber 100, the first casing 110and the second casing 190 cooperatively define a working section 195. Insome embodiments, and as illustrated, the working section 195 is aU-shaped indentation (or notch) in the side of the vapor chamber 100.

In some embodiments, the plurality of first support structures 154 andsecond support structures 176 contact the first inner surface 119 andthe second inner surface 199 of the first casing 110 and the secondcasing 190, respectively, and thereby support the first casing 110 andthe second casing 190 of the vapor chamber 100.

Referring to FIG. 1D, the evaporator section 114 is recessed in thecentral portion of the first inner surface 119 of the first casing 110.The evaporator section 114 includes a plurality of heat transferstructures 140 disposed on the first inner surface 119. In anembodiment, the plurality of heat transfer structures 140 arerectangular, plate-like structures that are disposed on the first innersurface 119 with the longer edge of the heat transfer structure 140 incontact with the first inner surface 119. The plurality of heat transferstructures 140 are surrounded by the sidewalls of the evaporator section114. In some embodiments, the plurality of heat transfer structures 140are disposed perpendicular to the first inner surface 119. However, inother embodiments, the plurality of heat transfer structures 140 aredisposed on the first inner surface 119 at an angle greater than zeroand less than 90°.

The vapor chamber 100 includes the condenser vapor flow area 120,evaporator vapor flow area 220E (FIGS. 2A and 2B), and an evaporatorvapor flow upper surface 120P. The condenser vapor flow area 120 is anarea where vapor flows in the condenser section 116.

The evaporator vapor flow upper surface 120P is a surface defined bycapillary structures (discussed below) on the surface of the heattransfer structures 140 and capillary structures (e.g., wick structure134) on the first inner surface 119. Vapor generated in the evaporatorsection 114 flows along the evaporator vapor flow upper surface 120P.The evaporator vapor flow upper surface 120P increases the surface areaof the capillary structures and thereby improves heat transferefficiency.

The at least one evaporator vapor flow area 220E is an area of theevaporator section 114 wherein vapor flows from the evaporator section114 to the condenser section 116 and in which the plurality of heattransfer structures 140 are absent. The evaporator vapor flow area 220Eis above the evaporator vapor flow upper surface 120P. In someembodiments, the evaporator vapor flow area 220E is an area in therecessed evaporator section 114 at the periphery of the recessedevaporator section 114 and in which the heat transfer structures 140 areabsent.

Referring briefly to FIG. 1E, in some embodiments, the first innersurface 119 and the second inner surface 199, one or more of theplurality of heat transfer structures 140, and one or more of theplurality of first support structures 154 include wick structures 201.The wick structures 201 are evenly distributed and substantially of thesame thickness. The wick structures 201 increase the heat transfersurfaces of the evaporator section 114 and reduce the high liquidpressure drop due to the capillary forces of the wick structures. In anexample, the wick structures 201 are sintered powdered wick structures201 that include copper. However, embodiments are not limited in thisregard. In other embodiments, other types of conductive wick structuresor combinations of different types of wick structures can be used. Forinstance, a screen mesh wick structure or groove wick structure or thelike, made of different types of materials or combination of conductivematerials other than copper can be used, depending on application andsize of the vapor chamber.

Returning to FIGS. 1A-1D, in embodiments, the first inner surface 119 inthe evaporator section 114 includes a wick structure 134, and isdisposed between the plurality of first support structures 154 andplurality of heat transfer structures 140. In some embodiments, thefirst casing 110 and the second casing 190 form an airtight vacuumchamber that contains working fluid and includes the plurality of firstand second support structures 154, 176, plurality of heat transferstructures 140, and wick structures 201.

In some embodiments, and as illustrated, the second casing 190 issubstantially planar. In embodiments, and as illustrated, the evaporatorsection 114 is centrally positioned and surrounded by the condensersection 116. The evaporator section 114 protrudes from the first contactsurface 112. Correspondingly, the evaporator section 114 is recessedfrom the first inner surface 119. However, the embodiments are notlimited in this regard. In other embodiments, the shape and size of thedifferent components of the vapor chamber 100 can be modified or adaptedas per design requirements, for example, to avoid (bypass) elements ordevices surrounding the heat source, while maximizing available heattransfer surface areas for improved thermal performance requirements.For instance, the first casing 110 is substantially planar and theevaporator section 114 is located in the second casing 190, theevaporator section can be located offset from a central position, and/orthere can be more than one recessed evaporator section (multi-recessed).In other embodiments, the transition of the first inner surface 119between the evaporator section 114 and the condenser section 116 is nota single step-like transition, as illustrated in FIG. 1D, but rather thefirst inner surface 119 between the evaporator section 114 and thecondenser section 116 includes multiple smaller steps (or “terraces”)such that the transition between the evaporator section 114 and thecondenser section 116 is a more gradual transition (multi-levelled). Thevapor chamber 100 can be shaped and sized (or otherwise configured) in adesired manner as long as a desired vapor pressure drop is obtained inthe vapor chamber 100, and the plurality of heat transfer structures 140and the plurality of first support structures 154 include the sinteredpowdered wick structures thereon. It should be noted that‘substantially’ as used herein, indicates that 50% or more of the firstcontact surface 112 and the second contact surface 192 are planar.

According to embodiments, the vapor chamber is a quadrangle-shapedstructure. However, in other embodiments, the vapor chamber can have avariety of shapes including a non-polygonal shaped structure, astructure including bends or curves or a combination thereof, withoutdeparting from the spirit and scope of the disclosure.

In some embodiments, the first casing 110 and the second casing 190 ofthe vapor chamber 100 can each be made of a single piece of conductivematerial, such as copper and the recessed evaporator section 114 havingthe plurality of first support structures 154 and the plurality of heattransfer structures 140 and the condenser section 116 having theplurality of second support structures 176 of the first casing 110 areintegrally formed. However, the embodiments are not limited thereto. Inother embodiments, other conductive materials can be used depending onthe application and size of the vapor chamber 100. In other embodiments,one or more components of the vapor chamber, for example, the recessedevaporator section 114, the plurality of first support structures 154,the plurality of heat transfer structures 140, the condenser section116, the plurality of second support structures 176 are obtained asindividual, discrete components that are connected to each other to formthe vapor chamber 100.

In some embodiments, the dimensions of the edges (or ends) of the firstcasing 110 and the second casing 190 is about 20 millimeters to about600 millimeters and the dimensions of the evaporator section 114 areabout 10 millimeters to about 60 millimeters. However, the embodimentsare not limited thereto. In other embodiments, the dimensions of thefirst casing, the second casing the evaporator section 114, and of othercomponents of the vapor chamber 100 can be increased or decreased asrequired by application and design of the vapor chamber 100, withoutdeparting from the scope of the disclosure.

In some embodiments, the thickness T (Z direction) of the first casing110 and the second casing 190 is about 0.5 millimeters to about 2millimeters, the depth D1 to the first inner surface 119 in thecondenser section 116 measured from the surface of the first bondingedge 118 and, correspondingly, the height of the plurality of secondsupport structures 176, is about 1 millimeters to about 50 millimeters,and the depth D2 to the first inner surface 119 in the evaporatorsection 114 is measured from the surface of the first bonding edge 118,and, correspondingly, the height of the plurality of first supportstructures 154, is between 1.5 millimeters to 55 millimeters. However,embodiments are not limited thereto. In other embodiments, the thicknessT, and the depths D1, D2 can be increased or decreased as required bythe application and design of the vapor chamber 100, without departingfrom the scope of the disclosure.

In some embodiments, the plurality of first and second supportstructures 154, 176 are column-shaped and the diameter of the pluralityof second support structures 176 is larger than the diameter of theplurality of first support structures 154. However, embodiments are notlimited thereto. In other embodiments, the diameter of the plurality ofsecond support structures can be equal to or smaller than the diameterof the plurality of first support structures 154, and the first andsecond support structures 154, 176 can have other sizes and shapes(e.g., other than column-shaped) depending on application and design thevapor chamber 100, provided the plurality of first and second supportstructures 154, 176 contact the first and second inner surfaces 119, 199of the first and second casings 110, 190, respectively, and adequatelysupport the first and second casings 110, 190.

In some embodiments, the thickness (Z direction) of the first bondingedge 118 and second bonding edge 198 is about 1 millimeters to about 3.5millimeters. However, embodiments are not limited thereto. In otherembodiments, the width of the first and second bonding edges can beincreased or decreased depending on the application and design of thevapor chamber, provided the first and second bonding edges 118, 198 canbe vacuum sealed and operational performance of the vapor chamber 100 issatisfactory.

FIG. 2A is a perspective top view illustrating the first casing 110 ofthe vapor chamber 100 of FIGS. 1A-1D having a working pipe 260,according to embodiments. FIG. 2B illustrates the evaporator section 114within the encircled portion 213 in relative detail. As shown in FIGS.2A and 2B, with continued reference to FIGS. 1A to 1D, the first casing110 includes the first inner surface 119 including the first bondingedge 118 along a peripheral edge thereof. The first inner surface 119includes the evaporator section 114 that is recessed in a centrallocation in the first inner surface 119. The plurality of second supportstructures 176 are disposed on the first inner surface 119 around theevaporator section 114 and in the condenser section 116. The pluralityof first support structures 154 are disposed on the first inner surface119 in the evaporator section 114. The vapor chamber 100 includes thecondenser vapor flow area 120, evaporator vapor flow area 220E, and anevaporator vapor flow upper surface 120P.

The plurality of heat transfer structures 140 are substantiallyrectangular in shape and have different lengths (in the radialdirection) with each extending radially (e.g., like spokes of a wheel)from a central portion of the evaporator section 114. The plurality ofheat transfer structures 140 are arranged in a staggered formation inthe radial direction. In other words, the corresponding radial ends(edges) of the heat transfer structures 140 in the length-wise directionare located at different radial distances from a central portion of theevaporator section 114. In addition, a single heat transfer structure140 is located in each radial direction. Stated otherwise, no two heattransfer structures 140 are collinear in a radial direction.

In other embodiments, the plurality of heat transfer structures 140 canbe non-rectangular shaped, collinear, and have the same lengths. In someother embodiments, the heat transfer structures 140 can be arranged inother than a radially extending configuration and/or in a non-staggeredfashion. The heat transfer structures 140 can be arranged in any desiredconfiguration provided a desired vapor pressure drop is obtained in thevapor chamber 100 and without departing from the scope of thedisclosure.

The plurality of first support structures 154 are arranged in a desiredpattern. The pattern may include the plurality of first supportstructures 154 arranged at regular intervals. Alternatively, theplurality of first support structures 154 may be arranged at irregularintervals. As illustrated in FIG. 2B, one or more first supportstructures 154 are arranged on top of heat transfer structures 140. Insome embodiments, some first support structures 154 contact the heattransfer structures 140. The plurality of second support structures 176are arranged in a desired pattern. The pattern may include the pluralityof second support structures 176 arranged at regular intervals.Alternatively, the plurality of second support structures 176 may bearranged at irregular intervals.

In embodiments, the plurality of first support structures 154, theplurality of heat transfer structures 140, and the plurality of secondsupport structures 176 are integrally formed, by stamping, CNC milling,or other methods. Alternatively, one or more of the plurality of firstsupport structures 154, the plurality of heat transfer structures 140,and the plurality of second support structures 176 are obtained asdiscrete components and coupled to the first inner surface 119 usingbonding techniques such as welding, diffusion bonding, thermal pressing,soldering, brazing, adhesive joining, a combination thereof, and thelike.

In some embodiments, the sintered powdered wick structure 201 of thefirst inner surface 119 is formed using a mold having the powdered wickstructure evenly distributed thereon. The mold is placed coveringstructures on the first inner surface 119 and then sintered. The size ofthe mold is adjusted such that the thickness of the sintered powderedwick structure on the inner surface 119 and the first support structure154 are substantially the same. As an example, the diameter of theportion of the mold covering the first support structure 154 is aboutthe same as the diameter of the first support structure 154 andthickness of the sintered powdered wick structure.

The first casing 110 includes a working pipe 260 secured to the firstbonding edge 118 of the first inner surface 119 in the working section195 thereof. The working pipe 260 is disposed in a gap or opening in theworking section 195 of the first bonding edge 118. The working pipe 260allows for fluid communication with the internal space 101 of the vaporchamber 100. The internal space 101 includes a working fluid that isintroduced into the inner chamber via the working pipe 260.

In order to introduce the working fluid, the second casing 190 is vacuumsealed to the first casing 110 using bonding techniques such as welding,diffusion bonding, thermal pressing, soldering, brazing, adhesivejoining or the like. The working pipe 260 is bonded using similartechniques. The working fluid is then introduced in the internal space101 via the working pipe 260. The opening of the working pipe 260 issealed (e.g., by flattening and bonding the ends) once the working fluidhas been introduced and air vacuumed out of the internal space 101. Theportion of the working pipe 260 extending from the edges is trimmed.

FIG. 3A is a perspective top view of the first casing 110 of the vaporchamber 100, according to other embodiments. FIG. 3B is a perspectiveview illustrating the evaporator section 114 in the encircled portion313 in FIG. 3A in relative detail. As shown in FIGS. 3A and 3B, withcontinued reference to FIGS. 1A to 1D, the plurality of heat transferstructures 140 in the evaporator section 114 of the first casing 110 aresubstantially rectangular-shaped and arranged parallel to each other ina staggered formation in the width direction (Y direction). Theplurality of heat transfer structures 140 have similar lengths, and twoor more (two illustrated) heat transfer structures 140 are arranged in arow (i.e., collinear). As illustrated, a single central heat transferstructure 140 is disposed in the central portion of the evaporatorsection 114. The central heat transfer structure 140 has substantiallywishbone shaped longitudinally ends 315. The ends are connected with aconnecting portion arranged in the central portion and parallel to theother heat transfer structures 140 in the evaporator section 114. Theevaporator vapor flow area 320E is defined adjacent the central heattransfer structure 140 and adjacent the longitudinally ends 315. Thewick structure 134 is omitted in FIGS. 3A and 3B for sake ofillustration; however, it should be noted that the vapor chamber 100includes the wick structure 134. In some embodiments, the wick structure134 includes a grooved wick structure, a sintered powder, or a metalmesh structure.

FIG. 4A is a perspective top view illustrating the first casing 110 ofthe vapor chamber 100, according to another embodiment. FIG. 4B is aperspective view illustrating the evaporator section 114 in theencircled portion 413 in FIG. 4A in relative detail. As shown in FIGS.4A and 4B, with continued reference to FIGS. 1A to 1D, the plurality ofheat transfer structures 140 in the evaporator section 114 of the firstcasing 110 are substantially rectangular-shaped and arranged in parallelextending away from a central portion of the evaporator section 114. Theplurality of heat transfer structures 140 are arranged parallel to eachother in the width direction (Y direction) and in the order ofincreasing lengths (X direction) from the central portion of the vaporchamber 100. Thus, the heat transfer structures 140 closest to thecentral portion are of the smallest length and the heat transferstructures 140 closest to the edges have the longest length. Theplurality of heat transfer structures 140 are arranged in rows eachincluding one heat transfer structure 140 that is parallel to heattransfer structures 140 in adjacent rows. The length of two centrallylocated heat transfer structures 140 is substantially the same. In someembodiments, two or more heat transfer structures 140 adjacent an edge(e.g., bonding edge 118) of the vapor chamber 100 having the longestlength. As illustrated, an evaporator vapor flow area 420E is definedadjacent the heat transfer structures 140 located in the centralportion. The wick structure 134 is omitted in FIGS. 4A and 4B for sakeof illustration; however, it should be noted that the vapor chamber 100includes the wick structure 134. In some embodiments, the wick structure134 includes a grooved wick structure, a sintered powder, or a metalmesh structure.

The vapor chambers 100 in FIGS. 2A to 4B include two evaporator vaporflow areas 220E (FIG. 2A), 320E (FIG. 3A), 420E (FIG. 4A). However, inother embodiments the vapor chamber 100 includes one (1) or more thantwo (2) evaporator vapor flow areas, and the evaporator vapor flow areascan have any desired location and have a desired shape or size asrequired by the application and design.

FIG. 5A is a perspective top view of the first casing 110 of the vaporchamber 100, according to another embodiment. FIG. 5B is a perspectiveview illustrating portion 513 of the evaporator section 114 in FIG. 5A.As shown in FIGS. 5A and 5B, with continued reference to FIGS. 1A to 1D,the plurality of heat transfer structures 140 in the evaporator section114 of the first casing 110 are substantially rectangular-shapedstrip-like structures arranged parallel to each other in the widthdirection (Y direction) in the evaporator section 114. However, in otherembodiments, the heat transfer structures 140 are arranged parallel toeach other in the length direction (X direction). The plurality of heattransfer structures 140 have similar lengths and each row includes oneheat transfer structure 140. One or more first support structures 154are located in some of the rows of the heat transfer structures 140.Thus, some rows of the heat transfer structures 140 are discontinuous(e.g., interrupted by presence of one or more first support structures154). The wick structure 134 is omitted in FIGS. 5A and 5B for sake ofillustration; however, it should be noted that the vapor chamber 100includes the wick structure 134. In some embodiments, the wick structure134 includes a grooved wick structure, a sintered powder, or a metalmesh structure.

An evaporator vapor flow area 520E is located surrounding the pluralityof heat transfer structures 140 and a height of the plurality of heattransfer structures 140 is minimized to increase the evaporator vaporflow upper surface 120P thereof.

FIG. 6A is a perspective top view of the first casing 110 of the vaporchamber 100, according to embodiments. FIG. 6B is a perspective viewillustrating portion 613 of the evaporator section 114 in FIG. 6A. Asshown in FIGS. 6A and 6B, with continued reference to FIGS. 1A to 1D,the plurality of heat transfer structures 140 in the evaporator section114 of the first casing 110 are substantially rectangular-shaped andarranged parallel to each other and in multiple rows in the evaporatorsection 114 and along the length dimension of the vapor chamber 100. Inan embodiment, and as illustrated, the evaporator section 114 includesseven rows of heat transfer structures 140, each row including multipleheat transfer structures 140 having the same length and arrangedparallel to each other. Each row of the heat transfer structure 140includes multiple first support structures 154. An evaporator vapor flowarea 620E is defined surrounding the plurality of heat transferstructures 140 and a height of the plurality of heat transfer structures140 is minimized to increase the evaporator vapor flow upper surface120P thereof. The wick structure 134 is omitted in FIGS. 6A and 6B forsake of illustration; however, it should be noted that the vapor chamber100 includes the wick structure 134. In some embodiments, the wickstructure 134 includes a grooved wick structure, a sintered powder, or ametal mesh structure.

FIG. 7A is a perspective top view of the first casing 110 of the vaporchamber 100, according to embodiments. FIG. 7B is a perspective viewillustrating portion 713 of the evaporator section 114 in FIG. 7A. Asshown in FIGS. 7A and 7B, with continued reference to FIGS. 1A to 1D,the plurality of heat transfer structures 140 in the evaporator section114 of the first casing 110 are substantially rectangular-shaped andarranged parallel to each other along the length dimension of the vaporchamber 100 in the evaporator section 114. The wick structure 134 isomitted in FIGS. 7A and 7B for sake of illustration; however, it shouldbe noted that the vapor chamber 100 includes the wick structure 134. Insome embodiments, the wick structure 134 includes a grooved wickstructure, a sintered powder, or a metal mesh structure. Each heattransfer structure 140 has a same length and are disposed in rows, eachrow including a single heat transfer structure 140. Multiple firstsupport structures 154 are disposed in each row of the heat transferstructure 140. An evaporator vapor flow area 720E is formed on one sideof the plurality of heat transfer structures 140 in the evaporatorsection 114.

FIG. 8 illustrates a flowchart of a method 800 for manufacturing a vaporchamber, according to embodiments of the disclosure. Methods consistentwith the present disclosure may include at least some, but not all, ofthe steps illustrated in method 800, performed in a different sequence.Furthermore, methods consistent with the present disclosure may includeat least two or more steps as in method 800 performed overlapping intime, or almost simultaneously.

In operation 810, it is determined whether all structures including theplurality of first support structures 154, the plurality of heattransfer structures 140, and the plurality of second support structures176 of the first casing 110 are to be integrally formed. If YES, thenthe method 800 proceeds to operation 820. If NO, then the method 800proceeds to operation 830.

In operation 820, if some of the structures of the plurality of firstsupport structures 154, the plurality of heat transfer structures 140,and the plurality of second support structures 176 are to formedintegrally, then these structures are formed integrally in the firstcasing and the remaining structures are bonded to the first casing 110.In operation 830, all structures are bonded to the first casing 110.Bonding techniques such as welding, diffusion bonding, thermal pressing,soldering, brazing, adhesive joining, a combination thereof, and thelike are used for bonding the structures to the first casing 110.

In operation 840, the second casing 290 is obtained. In operation 850,the sintered powdered wick structure 201 is evenly formed, havingsubstantially the same thicknesses, on the first inner surface 119 andthe second inner surface 199 of the first casing 110 and the secondcasing 190, respectively, the plurality of heat transfer structures 140,and the plurality of first support structures 154. The sintered powderedwick structure 201 is then inspected to ensure sintering and that thethermal performance of the wick structures is as desired.

After cooling, in operation 860, the working pipe 260 is inserted andsecured to the first bonding edge 118 of the first casing 110 at theworking section 195 thereof. Next, in operation 870, the second casing190 is placed on the first casing 110 and the first and second bondingedges 118, 198 of the first and second casings 110, 190 having theworking pipe 260 inserted and secured therein are bonded and sealed.Next, in operation 880, a working fluid is introduced into the workingpipe 260 and air is vacuumed out. In operation 890, the working pipe 260is closed, sealed, and a portion of the working pipe 260 protruding fromthe vapor chamber 100 cut. In an embodiment, the working pipe 260 isflattened and then bonded in order to close and seal the working pipe260. After cooling, working pipe 260 remaining after cutting is trimmed.

In some embodiments, the first and second casings 110, 190, theplurality of first and second support structures 154, 176, and theplurality of heat transfer structures 140 are made of copper. However,embodiments are not limited in this regard. In other embodiments, thefirst and second casings 110, 190, the plurality of first and secondsupport structures 154, 176, and the plurality of heat transferstructures 140 are made of other heat conducting materials having arelatively high thermal conductivity, as required by the application andsize of the vapor chamber 100.

In some embodiments, the working fluid includes deionized water.However, in other embodiments, working fluids includes methanol oracetone. Any desired working fluid can be used as long as the workingfluid is vaporized by the heat generated by a heat source and the vaporcan condense back to the working fluid and be drawn to the fiber wickstructure to flow back to the heat source.

Those of skills in the art will understand that, in other embodiments,further heat treatment processes can be employed during themanufacturing method of the vapor chamber.

In the embodiments, the vapor chamber can coupled to a processingcircuit (e.g., a processor) or any other circuit from which heat is tobe dissipated using fastening methods such as soldering, brazing orusing thermal paste combined with glue. Alternatively, other fasteningtechniques can be provided for ensuring direct thermal contact between asurface of the processing circuit and the vapor chamber.

Vapor chambers, according to embodiments discussed herein, generate acapillary force in the wick structure equal to or greater than theliquid pressure drop in the wick structures and vapor pressure drop inthe vapor chamber. The vapor chambers include the condenser vapor flowarea, the evaporator vapor flow area, and the evaporator vapor flowupper surface provide improved vapor pressure drop. The plurality ofheat transfer structures and the plurality of first support structureshaving the sintered powdered wick structures thereon increase the heattransfer surfaces of the evaporator section, and mitigate the highliquid pressure drop of the sintered powered wick structures having highcapillary forces. Fluid resistance to sustain capillary force drivenflow throughout the wick structures is decreased, increasing porosityand permeability of the evaporator section and providing improvedthermal performance. The plurality of first and second supportstructures support the first and second casings of the vapor chamber andprevent deformation or collapse of the first and second casings.

The present application has been described herein in an illustrativemanner, and it is to be understood that the terminology which has beenused is intended to be in the nature of words of description rather thanof limitation. Many modifications and variations of the presentembodiments are possible in light of the above teachings. The presentapplication can be practiced otherwise than as specifically describedwithin the scope of the appended claims. The subject matter of allcombinations of independent and dependent claims, both single andmultiple dependent, is herein expressly contemplated.

What is claimed is:
 1. A heat dissipating device, comprising: a firstcasing coupled to a second casing, the first casing including a recessedportion, wherein the recessed portion at least partially defines anevaporator section of the heat dissipating device, a condenser sectionof the heat dissipating device is disposed surrounding the recessedportion, the first casing and the second casing enclose an internalspace of the heat dissipating device, a plurality of first supportstructures are arranged in the recessed portion, a plurality of secondsupport structures are arranged in the condenser section, and aplurality of heat transfer structures are arranged in the recessedportion, wherein the plurality of heat transfer structures are elongatedstructures extending radially from a central region of the recessedportion.
 2. The heat dissipating device of claim 1, further comprising awick structure disposed in the recessed portion.
 3. The heat dissipatingdevice of claim 1, wherein at least one first supporting structure ofthe plurality of the first supporting structures is disposed on top of aheat transfer structure.
 4. The heat dissipating device of claim 1,wherein at least one first supporting structure of the plurality of thefirst supporting structures is disposed between two heat transferstructures.
 5. The heat dissipating device of claim 1, wherein theplurality of heat transfer structures are rectangular-shaped andarranged in a staggered formation in the recessed portion.
 6. The heatdissipating device of claim 5, wherein two or more heat transferstructures have different lengths.
 7. The heat dissipating device ofclaim 1, wherein a single heat transfer structure is located in eachradial direction.
 8. The heat dissipating device of claim 1, wherein oneor more first support structures of the plurality of first supportstructures contact one or more heat transfer structures.
 9. The heatdissipating device of claim 1, wherein one or more first supportstructures of the plurality of first support structures are separatedfrom the heat transfer structures.
 10. The heat dissipating device ofclaim 1, wherein the first casing includes a bonding edge along allsides of the first casing and enclosing the internal space, and at leastone side includes an opening in the bonding edge.
 11. The heatdissipating device of claim 1, wherein the first casing and the secondcasing each include an inner surface that faces the internal space, andwherein a wick structure is disposed on each of the inner surfaces, oneor more of the plurality of heat transfer structures, and on one or moreof the plurality of first support structures.
 12. A method ofmanufacturing a heat dissipating device, comprising: obtaining a firstcasing including a recessed portion, wherein the recessed portion atleast partially defines an evaporator section of the heat dissipatingdevice, a condenser section of the heat dissipating device is disposedsurrounding the recessed portion, a plurality of first supportstructures are arranged in the recessed portion, a plurality of secondsupport structures are arranged in the condenser section, and aplurality of heat transfer structures are arranged in the recessedportion, wherein the plurality of heat transfer structures are elongatedstructures extending radially from a central region of the recessedportion; obtaining a second casing; securing a working pipe to the firstcasing; positioning the second casing on the first casing; sealing thefirst casing and the second casing, and thereby enclosing an internalspace of the heat dissipating device; introducing working fluid in theinternal space; and sealing the working pipe and trimming a portion ofthe working pipe protruding from the heat dissipating device.
 13. Themethod of claim 12, further comprising: integrally forming one or moreof the plurality of first support structures, the plurality of heattransfer structures, and the plurality of second support structures inthe first casing.
 14. The method of claim 12, further comprising:bonding one or more of the plurality of first support structures, theplurality of heat transfer structures, and the plurality of secondsupport structures to the first casing.
 15. The method of claim 12,wherein the first casing and the second casing each include an innersurface that faces the internal space, and the method further comprises:forming a sintered powder structure on the inner surfaces, one or moreof the plurality of heat transfer structures, and one or more of theplurality of first support structures.
 16. The method of claim 12,further comprising vacuuming out air from the heat dissipating deviceprior to sealing the working pipe.
 17. The method of claim 12, whereinsecuring the working pipe to the first casing includes securing theworking pipe in an opening in one side in a bonding edge disposed alongall sides of the first casing and enclosing the internal space.
 18. Themethod of claim 12, wherein at least one first supporting structure ofthe plurality of the first supporting structures is disposed between twoheat transfer structures.
 19. The method of claim 12, wherein theplurality of heat transfer structures are rectangular-shaped andarranged in a staggered formation in the recessed portion.
 20. Themethod of claim 12, wherein a single heat transfer structure is locatedin each radial direction.